Referring to FIG. 1, a conventional magnetoelectric device includes a three-phase induction motor 1, and a generator 2 connected to the three-phase induction motor 1. The three-phase induction motor 1 is powered by an alternating current source (AC), and is configured to drive the generator 2 with fixed rotation speed and torsion force. For example, when apparent power provided by the alternating current source (AC) to the three-phase induction motor 1 is 1 KVA, the generator 2 may generate electrical energy output having real power of 1 KW. However, since the three-phase induction motor 1 (e.g., coils thereof) has inductive reactance that may generate reactive power, real power of the three-phase induction motor 1 is reduced. Accordingly, the power factor of the conventional magnetoelectric device is low, and electrical energy supplied by the alternating current source (AC) is wasted.